isBusinessEmail

isBusinessEmail provides a free API to determine whether an email address or domain belongs to a business, detecting Google Workspace and Microsoft 365 usage. The service offers up to 100 free checks per day, stores no email data, and is EU‑hosted, making it suitable for privacy‑focused applications. Users can obtain an API key instantly without a credit card, and the platform includes tools, lists, and integrations for developers.

isBusinessEmail publishes 4 API contracts indexed on the APIs.io network, including Check API, Feedback API, Health API, and 1 more. Tagged areas include Company, Email Verification, BusinessTools, and EU-hosted.

The isBusinessEmail catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

isBusinessEmail’s developer surface includes changelog, authentication, documentation, API reference, getting-started guide, support, engineering blog, and 23 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

40.1/100 developing ▼ -10.3 Agent 41/100 agent ready Heartbeat 100/100 alive Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

1 published contract

Company Email Verification BusinessTools EU-hosted

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 40.1/100 · developing

Contract Quality 10.6 / 19

Developer Ergonomics 4.5 / 15

Access Clarity 2.6 / 15

Operational Transparency 4.9 / 10

Contract Governance 2.0 / 9

Discoverability 4.8 / 8

Regulatory Posture 4.0 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 41/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 6 / 6

Protected Resource Metadata 5 / 5

Registration Without a Human 6 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Typed Event Surface +6 pts — AsyncAPI document, OR webhooks/callbacks objects in the as-published OpenAPI, OR common[].type includes Webhooks
Documented Reversibility +6 pts — a reversal operation in the contract, graded up when a window is documented too
Agent Skills +5 pts — skills artifact present, graded by who authored it

4 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Access Clarity scores 17.1 — up to +16.6 composite points
Developer Ergonomics scores 29.8 — up to +14.0 composite points
Contract Quality scores 56.5 — up to +10.9 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/isbusinessemail/apis.yml: open an issue on github.com/api-evangelist/isbusinessemail to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Standards implemented 3

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

OAuth 2.0 Protected Resource Metadata

measured — observed by APIs.io (verified)

Dynamic Client Registration

measured — observed by APIs.io (published)

OpenAPI

measured — observed by APIs.io (published)

APIs 4

Individual APIs this provider publishes, each with its own machine-readable definition.

isBusinessEmail Check API

The Check API from isBusinessEmail — 2 operation(s) for check.

isBusinessEmail Feedback API

The Feedback API from isBusinessEmail — 1 operation(s) for feedback.

isBusinessEmail Health API

The Health API from isBusinessEmail — 1 operation(s) for health.

isBusinessEmail Usage API

The Usage API from isBusinessEmail — 1 operation(s) for usage.

isBusinessEmail API pricing

Rate limits

Deep check daily limit: 1,000 deep checks a day
Feedback daily limit: 50 a day per key

Rate-limit details →

Rate Limits 1

Documented rate limits and quota policies.

Isbusinessemail Rate Limits

2 limits

RATE LIMITS

Service Levels 1

Uptime the provider promises or reports, as SLA4OAI. Read from its own pages; APIs.io runs no monitors.

isBusinessEmail

SLA

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Isbusinessemail Context

2 classes · 35 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

isBusinessEmail API Rules

13 rules · 10 errors 1 warnings 2 info

SPECTRAL

JSON Schema 1

Standalone JSON Schema definitions for this provider's data models.

CheckResult

29 properties

JSON SCHEMA

Security Posture 3

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Isbusinessemail Authentication

apiKey/http · 2 schemes

SECURITY

Isbusinessemail Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Isbusinessemail Vulnerability Disclosure

security.txt · contact published

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Isbusinessemail Agentic Access

6 operations · 3 acting

AGENTIC

Resources

Get Started 2

Portal, sign-up, and the first successful call

Login

GettingStarted

GettingStarted

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

LLMsTxt

LLMsTxt

WellKnown

WellKnown

Design & Contract 7

Pagination, idempotency, versioning, errors, and events

Spectral

JSONLD

Vocabulary

DataModel

Lifecycle

ErrorCatalog

Conformance

Scroll for all 7

Access & Security 5

Authentication, authorization, and security posture

SecurityTxt

SecurityTxt

Security

Security

Authentication

Authentication

VulnerabilityDisclosure

VulnerabilityDisclosure

DomainSecurity

DomainSecurity

Operate 5

Status, limits, changes, and where to get help

RateLimits

Deprecation

StatusPage

ChangeLog

Support

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 2

The organization behind the API

Website

Website

Blog

Blog

Other 2

Properties that don't map to a standard resource type

Hosts

Hosts

Vendors

Vendors

Source (apis.yml)

aid: isbusinessemail
name: isBusinessEmail
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  probe_state: gated
  source:
  - authentication
  - rate-limits
  - security
  generated: '2026-11-06'
  method: derived
image: https://isbusinessemail.com/og/default.png
description: isBusinessEmail provides a free API to determine whether an email address or domain belongs to a business, detecting
  Google Workspace and Microsoft 365 usage. The service offers up to 100 free checks per day, stores no email data, and is
  EU‑hosted, making it suitable for privacy‑focused applications. Users can obtain an API key instantly without a credit card,
  and the platform includes tools, lists, and integrations for developers.
url: https://raw.githubusercontent.com/api-evangelist/isbusinessemail/refs/heads/main/apis.yml
x-type: company
x-source: harvest:new-submission
x-tier: profiled
x-tier-reason: enrichment pass 2026-10-05 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-10-05'
modified: '2026-10-05'
tags:
- Company
- Email Verification
- BusinessTools
- EU-hosted
tags_raw:
- Company
- EmailVerification
- BusinessTools
- API
- EUHosted
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: AgenticAccess
  url: agentic-access/isbusinessemail-agentic-access.yml
- type: RateLimits
  url: rate-limits/isbusinessemail-rate-limits.yml
- type: Spectral
  url: rules/isbusinessemail-rules.yml
- type: JSONLD
  url: json-ld/isbusinessemail-context.jsonld
- type: Vocabulary
  url: vocabulary/isbusinessemail-vocabulary.yml
- type: DataModel
  url: data-model/isbusinessemail-data-model.yml
- type: Deprecation
  url: lifecycle/isbusinessemail-lifecycle.yml
- type: Lifecycle
  url: lifecycle/isbusinessemail-lifecycle.yml
- type: ErrorCatalog
  url: errors/isbusinessemail-problem-types.yml
- type: Conformance
  url: conformance/isbusinessemail-conformance.yml
- type: LLMsTxt
  url: llms/isbusinessemail-llms.txt
- type: SecurityTxt
  url: well-known/isbusinessemail-security.txt
- type: WellKnown
  url: well-known/isbusinessemail-well-known.yml
- type: Hosts
  url: hosts/isbusinessemail-hosts.yml
- type: Vendors
  url: vendors/isbusinessemail-vendors.yml
- type: StatusPage
  url: https://status.isbusinessemail.com
- type: Security
  url: https://isbusinessemail.com/security
- type: Login
  url: https://isbusinessemail.com/login
- type: ChangeLog
  url: https://isbusinessemail.com/changelog
- type: Authentication
  url: authentication/isbusinessemail-authentication.yml
- type: VulnerabilityDisclosure
  url: security/isbusinessemail-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/isbusinessemail-domain-security.yml
- type: Website
  url: https://isbusinessemail.com
- type: Documentation
  url: https://isbusinessemail.com/docs
- type: APIReference
  url: https://isbusinessemail.com/docs/api
- type: GettingStarted
  url: https://isbusinessemail.com/docs/quickstart
- type: Support
  url: https://isbusinessemail.com/contact
- type: Blog
  url: https://isbusinessemail.com/blog
- type: TermsOfService
  url: https://isbusinessemail.com/terms
- type: PrivacyPolicy
  url: https://isbusinessemail.com/privacy
apis:
- aid: isbusinessemail:isbusinessemail-check-api
  name: isBusinessEmail Check API
  description: The Check API from isBusinessEmail — 2 operation(s) for check.
  humanURL: https://isbusinessemail.com/docs/api
  baseURL: https://api.isbusinessemail.com
  tags:
  - Check
  properties:
  - type: OpenAPI
    url: openapi/isbusinessemail-check-api-openapi.yml
  - type: JSONSchema
    url: json-schema/isbusinessemail-check-result-schema.json
- aid: isbusinessemail:isbusinessemail-feedback-api
  name: isBusinessEmail Feedback API
  description: The Feedback API from isBusinessEmail — 1 operation(s) for feedback.
  humanURL: https://isbusinessemail.com/docs/api
  baseURL: https://api.isbusinessemail.com
  tags:
  - Feedback
  properties:
  - type: OpenAPI
    url: openapi/isbusinessemail-feedback-api-openapi.yml
  - type: JSONSchema
    url: json-schema/isbusinessemail-check-result-schema.json
- aid: isbusinessemail:isbusinessemail-health-api
  name: isBusinessEmail Health API
  description: The Health API from isBusinessEmail — 1 operation(s) for health.
  humanURL: https://isbusinessemail.com/docs/api
  baseURL: https://api.isbusinessemail.com
  tags:
  - Health
  properties:
  - type: OpenAPI
    url: openapi/isbusinessemail-health-api-openapi.yml
  - type: JSONSchema
    url: json-schema/isbusinessemail-check-result-schema.json
- aid: isbusinessemail:isbusinessemail-usage-api
  name: isBusinessEmail Usage API
  description: The Usage API from isBusinessEmail — 1 operation(s) for usage.
  humanURL: https://isbusinessemail.com/docs/api
  baseURL: https://api.isbusinessemail.com
  tags:
  - Usage
  properties:
  - type: OpenAPI
    url: openapi/isbusinessemail-usage-api-openapi.yml
  - type: JSONSchema
    url: json-schema/isbusinessemail-check-result-schema.json
x-submission-notes: Tilfortis MB (Lithuania).
x-submission-probe: api.isbusinessemail.com 200 JSON index; /openapi.json 200 (OAS 3.1); /mcp POST 401 'Connect with OAuth
  or send API key'; invented path 404 problem+json; /docs and llms.txt 200.
x-submitted-by: hello@isbusinessemail.com (apis.io/add, 2026-10-05T07:56:41.786Z)
x-coverage:
  state: gated
  reason: partner-login
  method: derived
  generated: '2026-10-05'
  generator: derive-coverage.py (pre-flight evidence)
  detail: the company serves an API surface but requires credentials before any description of it can be read
  evidence:
  - url: https://api.isbusinessemail.com/openapi.json
    status: null
  - url: https://api.isbusinessemail.com/mcp
    status: 401
  - url: https://isbusinessemail.com
    status: 200
x-enrichment:
  date: '2026-10-05'
  status: enriched
  artifacts_added: 22
  pass: modular-v1
  engine: identity=local,contract=local,surfaces=local,docs=local,regulatory=local

isBusinessEmail API — frequently asked questions

Does isBusinessEmail have an API?

Yes. APIs.io lists 4 APIs from isBusinessEmail, including isBusinessEmail Check API, isBusinessEmail Feedback API and isBusinessEmail Health API, and 1 more.

Is there an OpenAPI specification for the isBusinessEmail API?

Yes. APIs.io indexes 4 OpenAPI specifications for isBusinessEmail, each linked for download from this page.

How do I authenticate with the isBusinessEmail API?

isBusinessEmail documents its authentication (apiKey/http · 2 schemes). The details are profiled on APIs.io as Isbusinessemail Authentication.

Is the isBusinessEmail API ready for AI agents?

isBusinessEmail has a Kin Score of 40.1 out of 100 (developing) and an Agent Readiness score of 40.5 (agent-ready), scored by API Evangelist on 2026-11-06.

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